Carburetor



Nov. 10 1925- 56 .38

L A. WESTBO CARBURETOR Fil June 1921 '2 heets-Sheet 2 awventoz Zeonard A {Mast/b0 k Patented Nov. 10, 1925.

UNITED STATES PATENT GFFICE.

onnnun'nron.

Applicatiomfiled June 9,

To all whom it may concern:

Be it known that I, LEONARD A. WESTBO, a citizen of the United States, and a resident of the county of Pierce, State of Washington, have invented certain new and usful Improvements in Carburetors, of which the following is a-specification. My invention relates to improvements in carburetors, for use in connection with the engines of motor driven vehicles and for use in aeroplanes or the like.

The principal object of the present invention is to provide a carburetor wherein carburetion is automatically controlled by suction, or vacuum, produced in the operation of the engine pistons, and which is equipped with certain manually controlled means whereby a greater, or a lesser vacuum pres sure may be produced accordingly as is required to successfully meet varying climatic or atmospheric conditions, or conditions caused by a hot or cold engine, and to'accomplish this end in a simple manner.

More specifically stated, it is the object of the invention to provide a carburetor having an air inlet equipped with a valve that moves automatically under the influence of vacuum existing within the mixing chamber of. the carburetor, to control the flow of liquid fuel and air into the device and which maintains the same substantially in the same proportions under different loads and conditions.

A further object of the invention resides in the construction of a carburetor of the character within the area of the air intake opening, through which all air admitted to the engine must pass, is varied automatically by the valve that operates therein to meet all the difl'erent conditions and does not remain a constant area.

Another important object of the invention resides in the construction whereby all the airadmitted into the carburetor .is caused to pass through an opening about which the 1921. Serial No. 476,1 81.

Other objects of the invention reside in the means provided for manually adjusting the fuel feed control mechanism and in the details of construction of the various arts. In accomplishin these and other objects of the invention, proved details of construction, the preferredforms of which are illustrated in the accompanying drawings, wherein Figure 1 is a side view of, a carburetor constructed according to the present invention.

Figure 2 is a transverse, vertical, section of the same, particularly illustrating the fuel feed control and adjusting mechanism.

Figure 3 is a horizontal, sectional view, taken substantially on the line 33 in Fig. 2, and showing the disposition within the casing of the feed control mechanism.

Figure 4 is a sectional view, taken on the line 4-4 in Fig. 3, showing the assembled relation of the members of the fuel feed control mechanism. i

Figure 5 is a detail sectional View, illustrating the operation of the feed control mechanism, and showing, in dotted lines, the position of the air valve and parts 0 erated thereby at a time when fuel is being admitted.

Figure 6 is a side elevation of the adjust 1 designates the tubular, main casing, or

body, of the carburetor which is provided,

at its upper end, with a peri heral flange 2 whereby it may be'suitably xed to the intake manifold of an engine with which it is to be used, and at its lower end has a circular opening within which is fitted the upper end portion, or neck 3, of an extension 4 provided with a laterally directed have provided the imair intake opening 5. The lower portion of this chamber within the neck portion of the casing is a throttle valve 7. This latter may be of the butterfly type, and operated in the usual manner by means of certain connections, not shown, to be connected with the lever arm 8, Figure 1, which is fixed to the stem, or-shaft, whereon the valve isfixedt The extension member 4 is provided, ad

j acent the neck portion 3, with an outwardly extending, annular flange 9 that is adapted to seat against the lower end of the casing 1, and a gasket 10 is placed betwetn the flange and casing and the parts are drawn tightly together to prevent any possible leaka e, by means of a bolt 11 that is threa ed, at its upper end, in a spider 12, that extends diametrically across the upper portion of the housing, and at its lower end, extends through the bottom wall of the member 4 and is equipped with tightening nuts 13 whereby the latter member is held tightly in place.

15 designates a conduit which may lead from the source of fuel supply, and which is suitably connected with the channeled stem 16 of a valve tube 17 that is extended into and fixed within the lower wall 18 of a housing portion 19 that is cast integrally with the casing 1 at one side thereof, and

which embodies upper and lower pockets 20 and 21 opening into the chamber 6, for containing certain parts of the fuel feed control mechanism presently described.

Formed within t I e opening at the lower end of the casing body and into which the neck ortion of the .member 4 is extended, is an inwardly opening, annular groove 24, which is covered by the neck ortion of the member 4 formed in this nec portion, as shown best in Figures 3 and 5, at circumferentially spaced apart. intervals, are upwardly and inwardly directed fuel inlets 25 which register, at their outer or lower ends, with the groove 24 and, at their inner or upper ends, open into the lower end of the mixing chamber 6. about the air inlet opening and at a point where thevelocity of intaken air is the greatest.

A fuel feed channel 26 is formed horizontally within the lower wall 18 of the housing 19, and this isclosed at its outer end by means of a screwplug 27 and, at its inner end opens'into the groove 24 The upper end of the valve tube 17 extends'through the channel '26 terminating flush with the uppersu'rface thereof, and is provided with a transverse channel '29 'in registration with the channel 26, also with an opening 30 where through communication is provided between the interior of the tube and conduit 15 and channel 29, thereby providing for the flow of fuel oil from the supply. source into the groove 24 and then into the mixing chamber by discharge through the inlets 25. V

A valve stem 32 is located within the tube 17 and extended upwardly through the opening 30 and into the lower pocket of the housing 19. On this stem is fixed an upwardly pointed, 'conically tapered valve 33 adapted to move toward and away from the opening 30 which forms a seat therefor to control the flow therethrough and a coiled spring 3.4 is wound about the stem and bears against the valve to yieldingly retain it in such position that it normally closes the passage 30 and prevents flow of fuel into the carburetor. However, the valve may be unseated to permit such flow, by a downward pressure against the upper end of the valve stem, as is presently described.

Located within the extension member 4, and slidable along the bolt 11, is a valve 36. This is of conical form with its smaller end pointing downwardly and its larger upper end, which is provided with a short cylindrically formed portion, as indicated at 37,

of slightly smaller diameter than the opening into the mixing chamber. When the valve is at rest, itis disposed substantially at the level of the opening into the chamber. -The valve 36 is yieldingly supported at its lower end, upon a short, coiled spring 39 that is located about the lower end of the bolt 11 within a ocket 40 in the lower portion ofathe member 4, and yieldingly retaining the valve against u ward movement is a spring 41 that is coi ed about the upper end of the bolt 11 and which bears at one end against the upper surface. of the valve and at its upper end against the outer end .of a tension adjusting lever 42. The lever 42 is fixed on a control, shaft 43 that s rotatably, mounted in the pocket 20 formed n the housing 19 and which has a lever 44 fixed to the outer end thereof, Figure 1, whereby it may be connected with suitable adjusting mechanism.

' The flow of gasoline, or other liquid fuel used into the carburetor, is controlled by the movement of the ,valve 36, under the influence of vacuum created Within the cham- .her 6 by operation of the engine; certain mechanism being provided whereby movement of'the valve to a greater or lesser degree automatically provides that fuel to a greater or less amount be'admitted accordingly.

Referrin particularl to Figures 2, 3 and 5, 45 designates a lever which is pivotally mounted on a stem 46 that is extended horizontally throu h the housing 19 and ocket 21, and which fora purpose presenty described, is provided at one end with an adjusting knob 47 The lever has a bifurcated end overlying the valve 36 and the two, portions thereof are equipped with rollers'48 which engage the fiat upper surface of the valve. The opposite end of the lever, which is short and relatively close to the stem 46, is equipped with a single roller 49 which is adapted to operate along a fiat, edge surface 50 of a horizontally disposed plate 51 that is pivotally supported between two spaced apart legs 52 and 52' of an adjusting piece 53. This latter mem her is preferably formed from a single piece of sheet metal and comprises two spaced apart side plates 54 and 54 between which the lever 45 is mounted, and which are provided with apertures 55 for receiving the stem 46 so that this piece likewise is pivotally supported; The two plates 54 and 54 are connected across the top by a web portion. 57 and one of the plates is provided above the stem 46 with an upwardly extending shoulder 58 against which one end of a spring 59, which is mounted in a pocket 60 in the wall of the housing, bears to cooperate for adjusting the piece with an adjusting screw 61 which is threaded through the wall of the housing in such position that its inner end engages a flat surface or shoulder 62 on the other plate below the level of the stem 46; With this construction, adjustment of the screw 61 efl'ects the rocking of the piece 53 on the stem 46 and a radial movement of the legs 52 and 52 between which the plate 51 is supported.

A pin 65 is secured in the ends of legs 52,

52' and extendsacross the space therebe tween; and the plate 51 is provided witlra horizontal slot 66 through which this pin extends to support that end of the plate and provide for lengthwise adjustment of the latter between the supporting legs. The under portion of the plate 51 comprises a radially curved edge portion 6'? which lies opposite the flat edge 50, and an upwardly directed straight edge portion 68 which meets the curved portion at a point 69. This point engages a spring arm 70, that is disposed di-.

rectly above the, valve stem 32 and which is supported at one end by means or a screw 71, extended through the side wallet the housing 19, and at its opposite end is lllOV- ably supported from the lower surface oi the housing 19 and held in positionby a guide screw 72.

From theconstruction so far described, it will be seen that upward movement of the valve 36 will actuate the lever 45 to move the roller 49-against the plate 51 to cause the latter to move the spring "50 against the valve stem 32 to open the port 30 for the ad mittance of gasoline to the carburetor.

To normally prevent longitudinal movement of the plate 51 relative to its support-- ing pin, l have provided a plate 75 which is mounted on the stem 46 between the side plate 54 of the piece 53 and a wall of the housing 19 as shown in Figures 3 and 4. This plate has a fixed relation to the stem and may be turned to adjusted position thereby.

Extended inwardly from the lower edge of the plate 7 5 is a pin 77 that extends within an arcuate slot 78 the plate 51 being part of the'icircumference of a circle about a center that is substantially at the middle of the slot 66 at its opposite end. This construction and arrangement of parts provides that adjustment of the plate 75, by turning the stem 46, effects longitudinal shifting of the plate 51 along its slot 66 which brings the point of contact 69 of the plate 51 and spring closer or farther from its pivotal point of support and thereby makes the device more or less sensitive to the movement of the valve 36. l j

For retaining an adjustment of the plate 75, I provide a flexible spring arm or plate 80 mounted rotatably on the stem 46, adjacent the outside of the'plate and this is connected by means of a screw or stud 81, that extends through the spring plate and also through a slot 82 in the plate 75, with the face plate 54 of the piece 53. The connection provided retains the parts 53 and plate always in the same relation, but since the slot 82 is formed arcuately about the stem 46 as acenter, adjustment of the plate-75 does not cause any movement of the piece 53. The lower end of the spring arm 80 has a detent 84'which is adapted to seat within any of a plurality of recesses 85 formed in the face of the plate 75 so that the plate 7 5 will be yieldingly held at different points of adjustment.

Along the under edge of the plate 7 5' is fixed a spring arm 86, which, at its outer end, has a adapted to bear against the under, radially curved edge 6? of the plate 51 to retain the latter yieldingly in place and against the roller Assuming that the parts of the device are so constructed, and are assembled as described, the operation of the carburetor would he asftollows:

laterally extending wing 87 Upon. the starting of the engine, there will be, due to the operation of the pistons, a vacuum created within the mixing chamber 6, which will cause the valve 36 to be raised against the pressure of the spring 41 and the lever 45 to be rocked to cause the roller 49 to engage the plate 51, and the latter to engage the spring arm 70 to cause it to press against the end of valve stem 32 and unseat the "valve 33 from the opening 30 to permit a flow of gasoline into the groove 24. The suction or vacuum produced by the enginecauses discharge of the gasoline into the mixing chamber 6 through the several inlets 25 and this mixes with the incoming air to form the carbureted air for the engine.

To get the proper'adjustment for ordinary running, the lever arm 42 is adjustedto an upper position, the screw 61 is then adjusted to move the piece 53 to raise or lower the legs 52-52 and plate 51 supported thereby 7 from or against the spring 7 which controls the inlet of gasoline until the engine operates properly for a speed of about twenty miles per hour. Should it become later necessary for further adjustment due to changes to atmospheric pressure, or other variable conditions, or if it is desired to get a finer adjustment, this may be done by manipulation of the knob 47 of the stem 46 which efi'ects shifting of the plate which through the connection with the plate 51 changes the distance between the pivot point of the plate inlets is readily taken-up, thoroughly mixed and atomized. It is further noted that since the valve 36 which controls the air inlet is mounted upon the spring 39 which may be compressed to \permitthe valve to move downwardly below the level of the air inlet opening 5 to provide an outlet for mixtures exploded within vthe carburetor or for charges that backfire within the manifold, danger of damage to the carburetor mecha nism or the interrupting the flow of fuel by such premature explosions is thereby avoided. 1

Having thus described my invention, what I claim as new therein and desire to secure by Letters-Patent is 1. In a carburetor comprising in combination, a mixing chamber, an air inlet, a valve for controlling the flow of air through said inlet in accordance with the degree of vacuum produced in the mixing chamber, a valve movable to control the flow of fuel oil to the mixing chamber, a supporting shaft, a lever pivotally mounted on said shaft between its ends and having one end engaging and movable in accordance with the air inlet valve, an adjustment piece pivotally mounted on the said shaft, a plate pivotally supported from said piece and engaged by the other end of said lever to be rocked thereby to actuate the fuel valve and an adjustment means for the adjustment piece whereb the efiective movement of the plate may e varied.

\ 2. A carburetor comprising in combination, a mixing chamber and an air inlet, a valve for controllin the flow of air through said inlet in accor ance with the degree of vacuum produced in the mixing chamber, a valve controlling the flow of fuel to the mixing chamber, a yieldable arm for actuating the valve, a rotatable supporting shaft, a lever pivotally mounted on said shaft with one end engaging and movable in accordance with the air inlet valve, an adjustment piece pivotally mounted on the said shaft, provided with spaced apart, depending legs, a plate pivotally mounted at one end between said legs and engaged at its other end by the other end of said lever and movable by the lever to engage said yieldable arm to actuate the fuel valve, and an adjusting means for the adjustment piece whereby the effective movement of the valve actuating plate may be varied.

3. In a carburetor comprising a mixing chamber and an air inlet, a valve movable to admit air in accordance with the degree of vacuum in the mixing chamber, a valve operable to control the flow of fuel to the mixing chamber, a stem for actuating the fuel control valve, a rotatably adjustable shaft, an adjustment piece pivotally mount- I end opposite that which is slotted, wherebv the plate may be movedto actuate the fuel control valve, means for adjusting the adjustment piece to move the point or support of the valve actuating plate, and means operable by rotation of the adjustable shaft for shifting the plate within the adjustment piece.

4. In a carburetor a casing comprising a mixing chamber and an air inlet, a valve mounted in said inlet to admit air in accordance with the degree of vacuum produced in the mixing chamber, a valve operable to control the flow of fuel to the mixing chamber, an actuating stem for said valve, an arm overlying said stem and movable into actuating relation therewith, a rotatably adj ustable stem rovided with a turning knob exteriorly o, the casing, an adjustment piece rotatable on the stemhaving a pivot pin fixed thereto, a valve actuating plate provided at one end with a slot through which said pivot pin extends, a projection on said plate engageable with the valve actuating arm, a lever, pivotally mounted on the shaft having engagement at one end with the air inlet valve and at its other end with the valve actuating plate, a plate fixed to the said shaft having a series of recesses therein and having a pin and slot connection with the valve actuating plate whereby the latter may be adjusted to vary its effective movement, a spring member fixed relative to the adjustment piece and having a detent 10 thereon for seating in said recesses to retain the shaft at adjusted positions and an adjustment screw for setting the adjustment piece.

Signed at Seattle, Washington, this 2nd day of June 19 L 21. EONARD A. WESTBO. 

